Sample pulverizing apparatus

ABSTRACT

An assembly apparatus for pulverizing solid samples, particularly samples of minerals, wherein is provided a plurality of elongated, hollow members joined together for simultaneous rotary movement. A sample is placed in each member along with at least one grinding element such that upon closing the hollow members with a unitary closure element and rotating the assembly, the grinding elements reciprocate from end to end of the hollow members to pulverize the samples. A stationary discharge element is positioned to receive pulverized material upon completion of the pulverizing operation.

United States Patent Everett SAMPLE PULVERIZING APPARATUS [75] Inventor:Peter Kenneth Everett, Cammeray,

New South Wales, Australia [73] Assignee: Mining Systems Limited, HongKong, Hong Kong [22] Filed: Jan. 14, 1972 [21] Appl. No.: 217,888

[30] Foreign Application Priority Data Jan. 19, 1971 Australia 3748/71[52] U.S. Cl. 241/137, 241/176 [51] Int. Cl. B02c 17/06 [58] Field ofSearch 241/30, 137, 176, 179, 241/180; 51/164 [56] References CitedUNlTED STATES PATENTS 754,122 3/1904 Bucklin 241/137 X 1,144,272 6/1915West 241/137 X Aug. 20, 1974 2,160,169 5/1939 Pontoppidan 241/180 X3,218,041 11/1965 Kubodera 51/164 X 3,583,647 6/1971 Paterson 241/137Primary Examiner-Donald G. Kelly Attorney, Agent, or FirmFitzpatrick,Cella, Harper & Scinto [5 7 ABSTRACT An assembly apparatus forpulverizing solid samples, particularly samples of minerals, wherein isprovided a plurality of elongated, hollow members joined together forsimultaneous rotary movement. A sample is placed in each member alongwith at least one grinding element such that upon closing the hollowmembers with a unitary closure element and rotating the assembly, thegrinding elements reciprocate from end to end of the hollow members topulverize the samples. A stationary discharge element is positioned toreceive pulverized material upon completion of the pulverizingoperation.

3 Claims, 4 Drawing Figures SAMPLE PULVERIZING APPARATUS The presentinvention relates to an apparatus for and a method of pulverizing solidsamples, more particularly samples of minerals.

In the conventional method of preparing mineral or rock samples foranalysis the samples are normally subjected to the following treatments:

a. crushing, usually to 7% inch inch size;

b. further size reduction to, for example, 100 mesh;

0. fine grinding to from 200 to 300 mesh; and

d. drying.

The conventional method suffers from the disadvantage that it is timeconsuming, and therefore costly, in that normally only one sample can betreated at the one time and the apparatus used must be thoroughlycleaned after treating each sample.

An object of the present invention is to overcome the above-mentioneddisadvantage of the conventional method of preparing samples for ananalysis by providing an apparatus for the preparation of such sampleswhich allows a large number of samples to be individually treated at theone time.

In accordance with the present invention, there is provided an apparatusfor pulverizing of solid samples which comprises a plurality ofelongated hollow members held together in side-by-side relationship,closure means adapted to seal each end of the hollow members, at leastone grinding element positioned in each of the hollow members, and meansto impart rotary motion to the plurality of hollow members whereby thegrinding elements move from end to end of the hollow members therebypulverizing samples contained in the hollow members.

This invention also provides a method of pulverizing solid samples,wherein the samples are placed in an apparatus as defined above androtary motion imparted to the plurality of hollow members.

The hollow members are preferably between one inch and three inches indiameter and between one foot and three feet long. The number of hollowmembers is preferably between and 200.

The hollow members are preferably arranged with their tops in one planeand their bottoms in another, parallel, plane.

The apparatus may be constructed from a large number of pipes or tubes,which may be joined together to form a rigid element. Alternatively theapparatus may be made by casting a block containing the hollow membersor cylindrical cavities may be bored in a solid block of material.

A single sheet of hardened steel or other material, with suitablereinforcing, which is clamped over their tops or bottoms, can be'used toclose the hollow members. Alternatively individual covers for eachhollow member may be fixed to a single sheet of material, allowing thesealing of a large number of hollow members with a single movement.Gaskets of rubber or other material may be used to improve the sealing.

The apparatus is operated by first covering all the bottoms of hollowmembers and then inserting a sample into each hollow member, the amountof sample usually being between fifty and five hundred grams of materialwith a maximum particle size of half an inch.

A grinding element is then inserted in each hollow member. The grindingelements usually take the form of hardened rods from half an inch to 2inches in diameter and 2 inches to 12 inches long.

Alternatively spherical or other shaped grinding elements may be used.Several grinding elements may be inserted in each cavity if it isconsidered desirable.

The tops of the hollow members are then sealed and covers with specialsound insulating properties may be attached over the sealing plates.

A means of rotating the block containing the hollow members is provided.The machine is rotated at between 10 r.p.m. and r.p.m. around ahorizontal axis of rotation at 90 to the longitudinal axes of the hollowmembers.

The rotary motion imparted to the block may be in the form of simpleharmonic oscillations rather than a continuous rotation.

As the hollow members rotate the grinding elements slide from one end ofthe hollow members to the other and accomplish grinding of the samplesby impact on the plates sealing their tops and bottoms and also bycontact against the walls of the hollow members.

The fineness of the materials is controlled by the time of grinding,which is usually between half an hour and five hours.

I During this period the block may be heated by any suitable means and,if considered desirable, the block may be equipped with gaskets of a gaspermeable substance to allow moisture and other gases to leave thehollow members.

When the desired fineness is achieved the rotation is stopped and thetop sealing plate is removed.

In a preferred embodiment the apparatus according to the invention isprovided with envelopes, of paper or other suitable material, in a sideby side relationship corresponding to the hollow members. A restrictingdevice may be fitted over each envelope to prevent passage of thegrinding elements, if considered desirable.

The discharge device is clamped over the tops of the hollow members, theblock is rotated through and the samples discharged into the envelopes.The discharge device may be designed so that the envelopes may beremoved one by one, or all together, without permitting discharge of thegrinding elements.

If considered desirable, discharge can be into paper or plastic cupsheld together so that they correspond to the tops of the hollow members.

After removal of the discharge apparatus the machine may be cleaned bypushing a brush or other device through each hollow member.

The apparatus and method .according to the invention will now beexemplified by reference to the embodiment shown in the accompanyingdrawings.

FIGS. 1 (A) and l (B) show, in longitudinal and transverse cross-sectionrespectively, the general arrangement of the hollow members (1). Anelectric heater (2) which fits inside a hollow axle (3) is shown. Theaxle is provided with a means of rotation to cause cylindrical grindingelements (4) to move from one end of the hollow members to the otherthereby grinding the samples.

A plate at the top (5) sealing the hollow members is clamped in positioncorresponding to bottom plate (7) which is shown in its operatingposition. Sound proofing covers (6) are shown.

FIG. 2 shows, in longitudinal cross-section, the general arrangement ofa sample discharge device. Paper envelopes (1 1) are fixed to cones (8)which are held in a relationship corresponding to the hollow members.

FIG. 3 shows, in cross-section, the construction detail of one conicaldischarge section. A cone (8) rests in a rectangular plate (9). A rod(10) passes through the cone in order to prevent the grinding element(s)entering the paper bag (11) which is held in position by a small clip(12) attached to the side of the cone.

The apparatus of the present invention has a number of advantages ascompared with conventional sample treating apparatus. The apparatus issimple in construction and operation with all wearing parts, which canbe made of any suitable material, being inexpensive. Also, the apparatuscan handle samples having a large initial particle size, for example, upto onehalf inch, with the final particle size being variable at willsimply by varying the time of operation. Another distinct advantage ofthis apparatus is that a large number of samples, for example 200, canbe treated at the same time and that the final, ground samples can allbe simultaneously discharged from the apparatus. Also, the apparatus canbe readily adapted to simultaneously dry and pulverize samples with suchdrying being carried out rapidly without forming lumps. The apparatuscan also be readily adapted for quiet, dust-free operation. Finally theapparatus, consisting of smooth tubes with readily removable end caps,can be thoroughly cleaned in very simple manner after the treatment ofeach batch of samples.

lclaim: 1. An apparatus for pulverizing of solid samples which comprisesa plurality of elongated hollow members, means holding said memberstogether in side-byside relationship, closure means having individualclosure caps joined together to form a single operable element andadapted to seal each end of the hollow members, at least one grindingelement positioned in each of the hollow members, and means tosimultaneously impart rotary motion to the plurality of hollow membersto reciprocate the grinding elements from end to end of the hollowmembers to pulverize the samples contained in the hollow members, andstationary discharge means disposed adjacent said closure means.

2. An apparatus according to claim 1 wherein said elongated hollowmembers are of cylindrical configuration and are between about 1 inchand 3 inches in diameter and are between about l foot and about 3 feetin length, said grinding elements being an elongated rod of from aboutone-half inch to about 2 inches in diameter and between about 2 inchesand about l2 corresponding to each of said hollow members, baglikemembers removably mounted on said cone-shaped members for receivingpulverized samples from said hollow members respectively, and a rodpassing through said cone to prevent the grinding elements from enteringthe bag-like members.

1. An apparatus for pulverizing of solid samples which comprises aplurality of elongated hollow members, means holding said memberstogether in side-by-side relationship, closure means having individualclosure caps joined together to form a single operable element andadapted to seal each end of the hollow members, at least one grindingelement positioned in each of the hollow members, and means tosimultaneously impart rotary motion to the plurality of hollow membersto reciprocate the grinding elements from end to end of the hollowmembers to pulverize the samples contained in the hollow members, andstationary discharge means disposed adjacent said closure means.
 2. Anapparatus according to claim 1 wherein said elongated hollow members areof cylindrical configuration and are between about 1 inch and 3 inchesin diameter and are between about 1 foot and about 3 feet in length,said grinding elements being an elongated rod of from about one-halfinch to about 2 inches in diameter and between about 2 inches and about12 inches in length.
 3. An apparatus according to claim 1 wherein saiddischarge means comprises a plate member, a plurality of cone-shapedmembers carried by said plate member corresponding to each of saidhollow members, bag-like members removably mounted on said cone-shapedmembers for receiving pulverized samples from said hollow membersrespectively, and a rod passing through said cone to prevent thegrinding elements from entering the bag-like members.